Made without castings ???

[DavidF]

  I have seen many times  "made without castings"  Im curious as to peoples thoughts on this issue,  Is it that not having to make castings is appealing to them or what is it??  I personally enjoy making patterns and castings and find it to save much time and expense. There is safety to consider when dealing with molten metal, but there are also many added benefits to casting as well.  Im just curious as to what your thoughts are on casting and im surprised more arent doing it themselves on the forum....

[Peewee]

I have to admit casting myself has never even occurred to me,   probably because it would be another skill to learn and i have limited time for my hobby.

not to mention a happy marriage to maintain    and more equipment may be frowned upon 

[DavidF]

LOL peewee,  I know the feeling on the marriage thing. I need to do something special for my wife since all I have been doing lately is cleaning out garages and moving cars around from my dads and back to dads. Man what a nightmare!!

[stevehuckss396]

I think people just shy away from projects that involve casting because they are not setup for it. When i was a beginner I stayed away because I couldn't risk screwing up expensive castings. It takes time to get setup to do garage casting and alot of space to store the equipment when not in use. There is alot that goes with it and most don't want to bother so they look for the "casting free" projects.

[DavidF]

steve,  I understand where you are coming from. Yes there is a bit of equipment to build and set up, but I feel the good out weighs the bad.
Its just a personal opinion and nothing more.  Hopefully I can turn some heads and get more interested in casting as I feel it would be of great benefit to the hobby. But its not for everyone and I can undestand that as well.  Im about to try something new, it may not work out, but Ill have fun trying.  More on that one later on

[ReFlad]

David, I for one can see the many benefits of casting, but have not yet gone down that road.  How did you get interested in casting?  How did you learn the trade?  What advice would you have for some one who has never attempted casting but would like to learn?  Let us know!
Ronald

[Don1966]

David like I had said before I have the furnace I built, the sand, the coupe and drag. I just never started doing any casting yet. I have read all the books on making molds and doing the casting. It's just getting there and doing it that keeping me. I have so many things going at once here and it makes it hard to get motivated. 

Don

[Jasonb]

Well as one who makes quite a few engines without castings but hates the "barstock" look here are my reasons.

For a single item why put the time into making a pattern and then have to machine it when I can just fabricate.

I can make items that if cast would need several core boxes, loose pieces and probably a few test pours to get things right in less time. For example how much more work would this bit I've just finished need, its also hollow inside but a blind hole.



Fabrication gives me the largest choice of material, most home foundrys are limited to aluminium and maybe brass/bronze. So I don't have to worry about lightweight flywheels, lining cylinders or the wrong material on bare surfaces like bronze flywheel rims. Something like this pully would just look wrong with an alloy rim and the spokes are 1/4 x 1/8 at their thinnest so may be a few failed pours. Not to mention having to core the 4 bolt holes as they can't be drilled



With limited space that I want to give over to the hobby I don't have room to set up a foundry.

J

[Jo]

To add to Jason's comments:

Sometimes even when you have the castings it is quicker and simpler to fabricate the parts. Take for example my Armstrong Hydraulic engine Cotswold Heritage sell the castings do it in three sets, set two is a very nice and expensive ?200+ set of lost wax castings, 95% of these can be considered to be simple turning jobs from bar stock. The more complex lost wax castings such as the hydraulic pumps would be very difficult to hold to machine so whilst it will take a little while to make these odd few I will be fabricating them, much as Jason has shown .

Jo

[Deko]

Another factor here in the UK, would be the cost of fuel. Many old folk here cannot afford to heat there homes in winter, let alone afford fuel to melt metal.

Cheers Dek.

[DavidF]

I kinda stumbled into the casting just as a curiosity to see how it was done and my very first attempt was a success producing a useable part. I was hooked from the first melt.  I was also working for an industrial maintence company and had accumulated alot of good scrap brass and bronze that I wanted to put to use. Im into restoring old cars and am the go to guy when you cant find a part or need something fabricated in my area, casting was a great help for many projects and kept me from having to purchase large chunks of metal that 80% would have been turned into swarf.
  My first furnace was nothing more than a piece of pipe that I was using to burn yard waste in and I quickly descoverd how easily it could melt aluminum and then brass by adding a bit of draft. This furnace didnt cost anything to run, but it took a couple of hours to get a good bed of coals going so I decided to build a propane furnace.  My first propane powed furnace is made out of a coffie can, uses a harbor freight plumbing torch for its heat source, and is lined with a mix of fireclay sand and pearlite.  This furnace only cost a few dollars to make and melted brass and bronze easily but I quick found its size very limiting, the crucible was a 2" by 2" piece of pipe, Probably ideal for small models but I wanted bigger, so I constructed my next furnace that is made from a propane tank and lined with a commercial refractory good for 3200' F.  I have been using this furnace for 3 years now and have been very happy with it.  Its still a nice small furnace and doesnt take up alot of room (no more room than a bbq propane tank) and can melt 12 lbs of cast iron in 45 minutes from dead cold.  The down side is the a couple of the castings im working on now weigh 10 lbs so a bigger furnace is underway that will melt 60+ lbs of Iron.
  Casting isnt ideal for everyone or everything and you guys are so good at building up parts that I can see why you wouldnt bother getting into casting parts but there may be a time where casting is your best solution especially when you have to make multiples of the same part.
And the main thing I like is being able to melt scraps and save on buying materials, lets face it metals arent cheap.

[DavidF]

JasonB,  neither one of those parts would be difficult to cast, and the one part with the gussets is actually easier than the pully. I know that seems odd but its just a matter of how you split the part.  But like you said, would it be worth making a casting? probably not if you only need to make one.  Jason, you do some awsome work!!! 

[steamer]

I don't know....that part with the gussets would not be fun to pull from the mold....I'd say you would need a core or two there....

Dave

[DavidF]

I don't know....that part with the gussets would not be fun to pull from the mold....I'd say you would need a core or two there....

Dave

 Make the one flange removable and use a 3 piece mold box, no core necessary.  Im going to try lost wax iron casting real soon. Im not sure how well it will work out but something like that gusseted part would be an ideal canidate for the process.

[steamer]

Ahh   3 piece Box!    there's where I went wrong!   cool!

Dave

[ScroungerLee]

Here is my take on it.

I have made a simple coal fired foundry that readily melts aluminum.  I used it twice to melt down scraps an just made ingots from them.  I was just curious to see if i could get scraps melted, they werent even clean.

The result was so porous that when I made the body for a Kerzel hit'N'miss out of one of the ingots water seeped through it.  I was greatly amused, a little JB Weld fixed the problem, but I realized how far off I am from casting a good part.  I just need to find the time to work on those skills and meanwhile using bar stock gets me easier results.

On the other side I think casting a part is cool just so I get the "look what I can do!" feeling.  Also I am a cheapskate, and for some shapes more of piece of bar stock ends up as swarf than ends up as the resulting part.  That bugs me.

So, conflicting views on my end.  Overall I want to get to be able to cast parts just for the satisfaction.


Lee

[Bezalel]

Hi David
 
I share your passion for liquid metal and pattern making.
I acquired the skills well before getting into making little engines in fact.
 
Most of my furnaces have been built from old 20 litre paint drums and a few bits from the local garden supply centre.
 
I have a range of different burners that I venture would challenge Dek's paradigm on fuel cost.
 

Another factor here in the UK, would be the cost of fuel. Many old folk here cannot afford to heat there homes in winter, let alone afford fuel to melt metal.

Cheers Dek.

My preferred burner is a simple LPG burner that uses about the same amount of gas to melt 5 kg of Ali, as the BBQ does for a family get together.
 


My next preferred burner costs almost nothing for the fuel but requires a constant supply of 10 PSI of compressed air.
It is a Babbington burner, made out of a 2kg coffee can and a brass door knobb, capable of burning used engine oil straight from the sump. It does take a bit of messing around to get a smokeless flame with straight sump oil so I mix in a bit of diesel to make the oil flow better and get a smokeless  burn from start-up to shut down. But at the end of the day, I'm happy to pay for a little LPG 'coz it is a lot cleaner.
 

 

sorry can't seem to find the photos of it puming heat, these are from the construction log.

Any one who has not been bitten by the liquid metal bug is probably not likely persist with the necessary effort required for building foundry on a limited budget.
 
There is a bit of a steep learning curve but I reckon its worth it.
 
 

[Dan Rowe]

I do a bit of lost wax casting mostly silicon bronze. It is useful for small parts I need a bunch of.

My first casting was a simple one. I needed a 5/8" bronze bushing and I only had 1/2" stock. I had a gallon metal can with casting sand so I pushed a 3/4" rod in the sand. I used the big tip on the torch and used a hand held crucible, I poured the metal into the hole. The casting made a sound 5/8" bar.

Dan

[ScroungerLee]

I need to read up on lost wax casting, somehow it seems easier to me, not sure if that is true.  Can it be used for aluminum?

Lee

[Dan Rowe]

Lee,
The book I learned from is "Centrifugal or Lost Wax Jewelry Casting" by Murray Bovin.

I use a vacuum pump so it is really a simple form of pressure casting with the atmosphere supplying the pressure.

Aluminium should work fine but I have only cast copper alloys.

Dan

[DavidF]

I need to read up on lost wax casting, somehow it seems easier to me, not sure if that is true.  Can it be used for aluminum?

Lee

  I have done some lost wax aluminum castings and it does work, but I feel that heavier alloys work out better.  As far as easier then sand casting,  well lets just say small parts lost wax and large parts sand casting.  Its one of those detail and expense things although you can do large part in wax also.

[ScroungerLee]

Thanks for the answers.  It seems like a commitment to try sand casting, or maybe I just get overwhelmed seeing what others do.  The right sand, copes, whatever else, just to see if I can make a part I want.

Gotta start out simple somehow.  Maybe pour hot metal into Kitties litter box and see I'd I end up with metal poop shapes 

Lee

[DavidF]

Thanks for the answers.  It seems like a commitment to try sand casting, or maybe I just get overwhelmed seeing what others do.  The right sand, copes, whatever else, just to see if I can make a part I want.

Gotta start out simple somehow.  Maybe pour hot metal into Kitties litter box and see I'd I end up with metal poop shapes 

Lee

Petrobond makes it easy. Just do it and try not to think too much about the materials. After all, your just making a sand castle in reverse. Start simple and the rest will just come naturally...

[Bogstandard]

David,

Getting back to your opening post.

I would just love to be able to do my own casting, but limited space has always held me back. If I had the room to do it, I would be a very willing apprentice, but sadly, never to be.

But I would like to raise one point about casting and the beginner to machining.

Many beginners think that buying castings is an easy way to start into model engine making. Maybe if it is a very basic engine and all the machining instructions come with it, then you stand a chance of getting a runner.

But when you come to the more complicated castings, it can be a lot easier to fabricate the part rather than trying to machine a casting.
Once you get more into making and machining castings, then it becomes a completely new art to be mastered.

Don't get me wrong, I buy casting sets like they are going out of fashion, and this is not boasting on my part, I know how to hold and machine them to get the required result, but the average new starter can usually end up throwing a very expensive casting set under the bench because it has turned out a lot more difficult than expected.

To my way of thinking then, if you have the room, time and expected experience to machine the results, then yes, go for the making your own cast parts, but if you are new to this game, get a little experience first about how to fabricate your own bits. Just so that you don't fall flat on your face at the first hurdle, and maybe then losing interest in the whole art form that we have going here.

John

[black85vette]

To my way of thinking then, if you have the room, time and expected experience to machine the results, then yes, go for the making your own cast parts, but if you are new to this game, get a little experience first about how to fabricate your own bits. Just so that you don't fall flat on your face at the first hurdle, and maybe then losing interest in the whole art form that we have going here.

John

Agree with you John.  I am just starting my first casting set having made a few engines and gained some experience.  I am finding I am needing additional information on how to do some procedures.   Having the basic skills has helped a lot but there is still quite a bit I don't know.   The biggest issue I think is starting with a piece that has no flat or parallel surfaces.   I am going slow because unlike working in bar stock, if I screw up I can't just start that part again.

To the OP;  much like others my limiting factor is space.   My "shop" in one corner of my garage and I have just enough room to turn around and work around my lathe and mill.   No room for casting.   

[DavidF]

Boggs, you make a very good point about the castings being more difficult to hold on to and machine. I found my first couple of casting sets a real learning experence on how not to do things.  But one of the great things about having a home foundry is if you do screw up on machining a casting, you can just melt it back down and re cast it.

[metalmad]

Hi Dave
Learning experence is right, yesterday I made my first attempt at casting up an engine block and had a few issues.
The sand was a little too dry, I put the fill hole too close to the flask and despite the old bench vise I sat on top, the flasks seperated a little with the resault I ran out of metal and the block is half an inch too short at the sump end.
I am going to make some minor adjustments to my patterns and repour with the bulk of the mold in the lower flask this time and a lot more weight on top.
It was great fun, very exciting to do and for a first attempt not too bad, I feel I can get it much better next time.

[Bogstandard]

Pete,

Good first attempt, so you managed to get your sand sorted then?

Rick,

I am half way through a post about my machining of castings.
Everyone has their own way of doing things, this is my way.

http://www.modelenginemaker.com/index.php/topic,158.0.html

John

[metalmad]

Hi John
The sand is bit of a work in progress as I feel my way into new territory, I did another pour today with much wetter sand and although I see some shrinkage in the center, I think it is a usable block.
I'm not sure if the shrinkage is due to the wetter sand, pouring from the top or even the smaller spew, but as long as there is enough metal there for the Cam and lifters it should not worry anything.
Pete

[DavidF]

Thats looking good.  Wetter?  I assume your using greensand?? for shrinkage controll try using some large feeder blocks that sit up higher than the casting to supply aluminum to the block as it cools. You can also increase the hight of the sprue and riser to give more head pressure to help out with shrinkage. one last note using a known alloy like 356 gives better results than scraps. Yea I know im throwing alot out there with not alot to go on, but youll figure it out 

[metalmad]

Hi Dave
The sand was just from the landscaping shop mixed 10 to one with cat litter
the cat litter was unused so not green at all 
Pete

[Artie]

Love your thread mate, my love is in the actual casting and Id prefer to go to the effort to make the plugs/cores etc than fabricate (sometimes), different strokes for different folks.

One use Ive found is that I now have every size piece of bar stock I ever need, just need to do a casting. I often just make up strange sizes with excess melt, and put it into stock for whenever.... using a piece of timber pushed into the sand (open top) or made up ingot molds...

Good stuff mate, enjoy the journey... some brass bits...



became these...

[maury]

Metalmad, that is a nice casting, looks like you are on the track for making a nice model. In your post you mentioned not being sure why the shrinkage appeared. First off, aluminum is a nutrously bad metal for shrinkage and porocity, to me, one of the more difficult metals to cast. A few hints.
1) to avoid the shrinkage, use a riser. You could put it on the vent side of the casting, and make it about as big in dia as the coke can, and about half as tall. The rule is the cross section of the riser should be about 1 1/2 times the largest cross section you are trying to prevent shrinkage in. Put it as close to the casting as possible. Metal freezes in the mold from the thinnest cross section to the thickest, so for the riser to work it needs to feed through a still melted section to the thick section of the casting. Put the vent in the drag, and make the cross section thick.

2) For aluminum especially, you need to reduce turbulence in the mold. Feed the casting from the sprue through a gate in the drag. Turbulence causes oxidation of the metal, and with aluminum, the slag is about the same density as the metal. So the slag will not float up, it will be included in the casting.

3 If you need vents ( your sand is dense) you may make a ice pick poker with 1/16 or 3/32 drill rod and use it to vent at the top most features in the cope.

Good luck
maury
www.lonestarengineworks.com

[DavidF]

metalmad, looks like you got your greensand dialed in, I all ways had a habit of making mine too wet.  Here is a pick of what I mean about the feeder blocks and extended sprue and vent. This part was actually a fail because I put the cope on 180' out.

[DavidF]

Artie, nice bits of brass you have going on there, cant wait to see the rest of it!!!

[zeeprogrammer]

I don't think casting is in my future. But I sure enjoy reading about it. I'm impressed with the knowledge of material and process one has to have.

With respect to some comments about 'using casting for first engine'...I went down that route. I ended up buying 3 (or was it 4?) kits before I got a runner. At the time I knew more than I do now. By which I mean...I've learned how little I knew and how much more there is yet to learn. Also at the time...I didn't know about these forums, the kit was fairly inexpensive, and a video was available to take me through the steps. (Turned out the video was incomplete.)

Even kits that come with plain stock are iffy. They just save you the trouble of getting the odd bits of metal. Although some come with decent construction manuals that I found useful (and aggravating at times). But being a beginner I ended up buying more material anyway. Still...it was a help to know what I had to buy.

Now I'm building up some inventory and whenever I do buy some standard material, I'll get an odd bit of something 'just in case'.

So I'm on the side of using plain stock for a first engine.

Now some of you might be thinking...'uh...didn't you just get a dynamo  and boiler kit?'. Well yes. I'm still a beginner and for me...those kits fit into my way of learning. That is, when something is different or parts are hard to get or when a model is very new for me. I don't think my next engine will be from a kit. Might be from a casting set though 

[Bogstandard]

Zee,

Many kits and plansets grossly over engineer the engines.

So all those 'special' materials are just not needed in a lot of cases.

If you were building say a nine cylinder radial, or a highly stressed ic engine then yes, some exotic materials will need to be used for coping with the stresses involved. But on small scale models of air or steam engines, or even low power ic engines, then almost any materials could be used in their construction, as long as things like galling and expansion rates are taken into account.

Beginners tend to think that the correct materials shown on plansets and kits are definitely needed, but they are usually not, and they can spend great deals of time and money attempting to obtain what is shown on the plan, when in reality, a quick scrabble around in the scrap box can usually turn up something that will do the job admirably.

John

[zeeprogrammer]

Beginners tend to think that the correct materials shown on plansets and kits are definitely needed, but they are usually not, and they can spend great deals of time and money attempting to obtain what is shown on the plan, when in reality, a quick scrabble around in the scrap box can usually turn up something that will do the job admirably.

Yes, that was true for me as I knew virtually nothing when I started this hobby. Materials have been (and still is) a part of my learning. When I started all I knew was 6061 aluminum was a popular metal. I didn't know anything about types of steel or brass (other than surely there were different types). The kits gave me a starting point (along with the Doug Briney's book - 'The Home Machinist's Handbook' which I found immensely helpful to me).

I would note also that as a beginner I hardly had a scrap box. A bit of metal from the projects I did in that book. The scrap box really began with the first kit  With the first parts I screwed up and extra stock I had to obtain to replace them. 

By 'special' I didn't really mean exotic. As a beginner I meant the 'odd' bit or the 'more difficult to find'. For instance some bolts, or brass or copper tubing (that is often difficult to obtain until you learn more about vendors or hobby shops - or even gather a few friends like this forum that can help). Or like that armature for the dynamo I want to build.

We forget what we didn't know. And you kind of fell into that trap when you mention 'as long as things like galling...are taken into account'. I didn't know that when I started...and I'll probably forget that I didn't know that some day too. 

[Bogstandard]

Sorry about that Zee, I realised afterwards that the word 'galling' might be a problem to some people, but usually a quickie visit to Google sorts things like that out.

You should get your neighbours and friends involved in your metal acquisition.

I have told everyone I know not to throw anything away that has metal in it, until I can have a look at it.
It might mean you get a yard full of junk, but at least, all you have to do is to strip the stuff down, and I will guarantee that you will get more raw material than you could ever buy for the cost of a trip down to the garbage dump to get rid of the leftovers.
I have even been given long lengths of large diameter brass and bronze bar that someone had stashed in the back of their garage for years. Most probably picked up from their fathers garage many years before, and they have never found a use for it.
I have more stock than ever I could use in my lifetime, and even the local model engineers come to me to raid my stash boxes in the hope that there is something in there that will help with their builds. And I have never had to pay for any of it, so I don't expect them to pay for it either.

John

[Bezalel]

Snip>

You should get your neighbours and friends involved in your metal acquisition.

I have told everyone I know not to throw anything away that has metal in it, until I can have a look at it.
It might mean you get a yard full of junk, but at least, all you have to do is to strip the stuff down, and I will guarantee that you will get more raw material than you could ever buy for the cost of a trip down to the garbage dump to get rid of the leftovers.  Snip>

John

What John said 

When you have a furnace your trips to the dump are even less frequent.  For jobs that are more ornamental than structural, what its made of is more about final colour and melting temperature than it is about the chemical composition of the alloy.   
 
Bez
 

[DavidF]

I dont know how things are in other areas of the world, but around here metals are high dollar and its next to impossible to find non ferris scraps (cans not included) There are alot of scrappers running around that only see things as thier weight in metal and not thier antique or usefull value. I purchased a clausing lathe off the back of a scrappers truck for 200.00 for a friend of mine. it was a perfectly good lathe that was bound to be melted down into some junk crap. It scares me to think about all the good stuff that was just scrapped out for a few bucks worth of scrap metal. I cant find very much brass or bronze scraps any more so I had to crank up the heat on my furnace and go for iron (which I can still find some scraps of) to make what I want. salvage and pack rat what you can, you might not be able to in the next few years. 

[zeeprogrammer]

Yes google is great...once you know the term or concept to look for...or what to look for. Otherwise it's a bit of hit and miss.

I've found this (and prior) forum a more invaluable tool and reference. I try to use google when I come across terms or concepts I don't understand and get an answer there before bothering people here. Although sometimes I ask just so others (that no doubt are wondering the same thing as I) will see the answers too. You just can't substitute the direct knowledge and nuance of experience you can get here.

If I have any advice for a beginner it would be to join a forum.

I have few friends and don't interact with neighbors much. Not that I'm anti-social. Believe it or not I'm somewhat introverted and have great difficulty striking up conversations. The 'mask of zee' helps a lot' 

Still...word is getting around. Especially at work. We're moving a few miles down the road and they're getting rid of old equipment. Scored a nice dial indicator and a multi-meter and I've got my eye on a bunch of plate aluminum.

On a different note (somewhat from the thread talking about mags)...I often cruise google now as if I'm reading a magazine. Now that I've gotten a better handle on what to look for.

As a kid, the model engineering magazines had a huge influence on me. Better than comic books. And the advertisements were a big part of the enjoyment where you could see all the offerings and drool over things. But over time the articles got smaller, there were more and more of the same ads, and the price for value got out of hand. And...I hate to wait. The internet is a winner there too. But I do miss those magazines.

Side note: I've been keeping everything now. If it's bigger than a chip...it's in my scrap box.

[PatJ]

This is a really old thread, but I am getting really old too, so maybe a good fit?  Only a year, that is not nearly as crusty as I am.

Getting into castings is not an easy road from any prospective, for a number of reasons.

I set my entire shop up for bar stock work, and then had to compress everything to create space for mixing, molding, woodworking equipment for pattern making, and space for general foundry equipment.  I had to "go vertical" with wall mounted shelving, and an outdoor storage shed for non-essential equipment like my wife's car.

Learning foundry work has been much like learning how to machine model engines, it can be difficult and tedious to learn.

For machining, I had to learn how to read the machine dials, how to use all the bits, how to grip the material, types of bits, shapes of bits, drill and tap charts, thread types, metal types, finishing, silver soldering, etc.
The drawings I made were drawn 1:1 on paper, in a what-you-see-is-what-you-get fashion.

For a foundry, you have to start all over and learn an entirely new skill set.  Woodworking becomes critical.  Patternmaking is an art by itself.
Things to consider for patterns include draft angle, machining allowances, shrinkage, etc.
Drawings for patterns are nothing like drawings for the finished part, and you have to think about parting lines, core prints; all sorts of things.

To keep expenses reasonable, most backyard foundry eqipment is hand made from scraps of things.
Many burn waste motor oil to keep the fuel costs down.  Propane is also an easy and economical fuel for most types of castings.

I would guess that anyone with good general modeling skills would also be good at foundry work.
You get out of it what you put into it.

I have read the excellent posts here about how to machine castings, and as a result of those posts, I spend a considerable amount of time thinking about how to add bosses and other temporary projections to allow a cast part to easily be held and machined.  I have found that most commercial casting kits throw you under the train when it comes to giving you a good way to hold a part in the chuck or vice.

The most difficult part of casting for me is........................did you guess it?
Thats right, getting the sand to have good green strength so the pattern can easily be removed to make the mold.

I don't do lost wax, that is a whole new level, and not one that I am going to go to.
I will stick with sand, although I have converted to a self-hardening resin-binder sand, and that solves a world of problems, but is not an inexpensive way to go for just a few castings.

The big payoff is never having to make heavy machining cuts.  The worst case for me is a few skims of the surface, and perhaps drill a hole.
With silver soldering, you can avoid most heavy cuts too, but I love gray cast iron, and don't know of a way to silver solder it.

So you basically have to learn two hobbies, machining and foundry work.
It can be done, but takes time, effort, planning, and money, and the risks have to be well understood and avoided (burns, fumes, etc).

A good half way point for many is to make patterns, and then find a foundry to cast the part.
Unfortunately finding a foundry, especially an iron foundry, is about like finding a diamond, and about as expensive as buying a diamond.
It is really no fun going around begging a foundry to do a one-off small part in iron.
Pouring your own iron is not easy, but more fun than begging or getting denied multiple times, or getting qouted exhorbitant prices.

Foundry work, like model making, is addictive.
Once you get into it, you can't really do enough of it.
There is always that next more challenging project/engine.
Add 3D modeling to the mix and chances are you will need to consult a therapist.
But its fun, that is for sure.

Why do I post here?
I know a lot of these folks from old forum times, and have admired their work for years.

And I use people like JasonB's work as a gauge for my casting quality (sort of like a machinability index for metals).
Right now my castings are at about 20%JS (Jason scale, remember you heard it here first).
If I can get to 80% JS, I will be whistling Dixie and considering my work an overwhelming success, but that is a tall order, and the JS scale is like the Richter scale, the difficulty of achieving quality goes up exponentially as the numbers increase.